Chilling your Champagnes in the freezer will ruin their aromas and flavours, so plan ahead with buckets of ice and coolers for chilling.

How to chill Champagne
In a Champagne bucket: a bottle from your cellar plunged into a mixture of water and ice should reach the right temperature in 15 to 20 minutes.
In the refrigerator: lie the bottle down on the bottom shelf for three or four hours before serving; you can leave it there even longer, provided that the temperature remains constant; this way you will always have a ready chilled bottle to hand.

The right temperature
Champagne is best drunk chilled but never iced. The younger and livelier the Champagne, the cooler it should be served (8ºC). A mature or vintage Champagne will be perfect at 10ºC. Over-chilling will mean that the wine is too cold to release its aromas and flavours

The Cork
The shape and state of the cork, just like the gentle hiss or resounding pop upon opening, gives us an indication of how long the wine has spent in the bottle, and how long it has spent sitting on the shelf.
If the cork splays out at the bottom (a) it means that the bottle is fresh and the cork still wishes to find its original shape. If the cork tapers in at the bottom (b) it means that the bottle is old, you will only hear a gentle sigh as the cork is popped.

The Bubbles
The bubbles also show the age of the wine. Over the years the bubbles will gradually become smaller and smaller, before finally dying out.  A connoisseur will not be worried by the absence of bubbles in a very mature wine, something that might shock the uninitiated into believing that their wine is flat.